The Periodic Table Flashcards Preview

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Flashcards in The Periodic Table Deck (30)
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1
Q

What were the two ways to categorise elements until recently?

A
  1. Physical and chemical properties

2. Relative Atomic Mass

2
Q

How did Newlands arrange the elements?

A

In rows of seven.

3
Q

Why did Newlands arrange the elements in octaves?

A

He noticed that every eighth element had similar properties.

4
Q

Why did Newlands table not work?

A

The transition metals messed up the pattern.

5
Q

Why was Newlands’ work criticised?

A
  1. Elements that didn’t have similar properties were grouped together
  2. Non-metals and metals were mixed
  3. No gaps left for undiscovered elements
6
Q

How many known elements were there in Mendeleev’s time?

A

Around 50.

7
Q

How did Mendeleev arrange the elements?

A

In order of atomic mass.

8
Q

Why was Mendeleev’s table successful?

A

Newly discovered elements fitted into gaps that he left.

9
Q

Why were the gaps clever?

A

They predicted the properties of undiscovered elements.

10
Q

Why was the periodic table largely seen as unimportant when it was first released?

A

There wasn’t much evidence to suggest that the elements really did fit together like that.

11
Q

Why is there less attraction for electrons in higher energy levels?

A
  1. Increased distance

2. Increased shielding (other inner electrons)

12
Q

Why does increased distance and shielding mean in terms of reactivity?

A

Outer shell electrons are more easily lost, but it’s harder for high energy levels to gain electrons.

13
Q

What are the group one elements also known as?

A

Alkali metals.

14
Q

How do the elements change as you go down group 1?

A
  1. More reactive

2. Lower melting and boiling points

15
Q

What properties do alkali metals share?

A
  1. Low density
  2. One outer electron
  3. React with water to produce hydrogen gas
  4. Form ionic compounds with non-metals
16
Q

What kind of ion do alkali metals form?

A

1+ ions.

17
Q

What colour compounds do alkali metals form with non-metals, and what colour solutions?

A

White compounds that dissolve in water to form colourless solutions.

18
Q

What is produced in the reaction between water and alkali metals?

A
  1. Hydrogen gas

2. Hydroxides - alkaline solutions

19
Q

What happens when alkali metals are put in water?

A
  1. Float
  2. Move around surface
  3. Fizzing
20
Q

What are the group seven elements also known as?

A

Halogens.

21
Q

How do the elements change as you go down group 7?

A
  1. Less reactive
  2. Higher melting point
  3. Higher boiling point
22
Q

What kind of elements are the halogens?

A

Non-metal coloured vapours.

23
Q

What kind of bonds do the halogens form with metals?

A

Ionic bonds.

24
Q

What kind of ions do the halogens form?

A

Halide ions (1-)

25
Q

How do halogens react with other halogens in an aqueous solution of its salt?

A

More reactive halogens displace less reactive halogens.

26
Q

What properties do transition metals share?

A
  1. Good conductors of heat and electricity
  2. Dense, strong, shiny (more than alkali metals)
  3. Less reactive (than alkali metals)
  4. Higher melting points (than alkali metals)
27
Q

What is special about the ions that transition metals form?

A

They often have more than one ion.

28
Q

Why are compounds colourful?

A

Due to the transition metal ion they contain.

29
Q

What colours do transition metal ions give?

A
  1. Gemstones

2. Pottery glazes

30
Q

What other use do transition metals have?

A

Good catalysts (e.g iron, Haber process)